Physical Sciences and Mathematics Commons^™

Climate Evolution Across The Mid-Brunhes Transition, Aaron M. Barth, Peter U. Clark, Nicholas S. Bill, Feng He, Nicklas G. Pisias

School of Earth & Environment Departmental Research

The Mid-Brunhes Transition (MBT) began ∼ 430 ka with an increase in the amplitude of the 100 kyr climate cycles of the past 800 000 years. The MBT has been identified in ice-core records, which indicate interglaciations became warmer with higher atmospheric CO2 levels after the MBT, and benthic oxygen isotope (δ18O) records, which suggest that post-MBT interglaciations had higher sea levels and warmer temperatures than pre-MBT interglaciations. It remains unclear, however, whether the MBT was a globally synchronous phenomenon that included other components of the climate system. Here, we further characterize changes in the climate system across the MBT …

Binding Of Telomestatin, Tmpyp4, Bsu6037, And Braco19 To A Telomeric G-Quadruplex-Duplex Hybrid Probed By All-Atom Molecular Dynamics Simulations With Explicit Solvent., Holli-Joi Sullivan, Carolyn Readmond, Christina Radicella, Victoria Persad, Thomas J Fasano, Chun Wu

College of Science & Mathematics Departmental Research

A promising anticancer therapeutic strategy is the stabilization of telomeric G-quadruplexes using G-quadruplex-binding small molecules. Although many G-quadruplex-specific ligands have been developed, their low potency and selectivity to G-quadruplexes over duplex remains unsolved. Recently, a crystal structure of a telomeric 3' quadruplex-duplex hybrid was reported and the quadruplex-duplex interface was suggested to a good target to address the issues. However, there are no high-resolution complex structures reported for G-quadruplex ligands except for a docked BSU6037. In this study, molecular dynamic (MD) binding simulations with a free ligand were used to study binding poses and dynamics of four representative ligands: telomestatin, …

Evolution Of 21st Century Sea Level Rise Projections, Andra J. Garner, Jeremy L. Weiss, Adam Parris, Robert E. Kopp, Radley M. Horton, Jonathan T, Overpeck, Benjamin P. Horton

School of Earth & Environment Departmental Research

The modern era of scientific global‐mean sea level rise (SLR) projections began in the early 1980s. In subsequent decades, understanding of driving processes has improved, and new methodologies have been developed. Nonetheless, despite more than 70 studies, future SLR remains deeply uncertain. To facilitate understanding of the historical development of SLR projections and contextualize current projections, we have compiled a comprehensive database of 21st century global SLR projections. Although central estimates of 21st century global‐mean SLR have been relatively consistent, the range of projected SLR has varied greatly over time. Among studies providing multiple estimates, the range of upper projections …

Development Of Betulinic Acid Triazole Conjugates As Potential Anti-Cancer Agents, Gayathri Jampana

Theses and Dissertations

Betulin and betulinic acid are pentacyclic triterpenoid natural product isolated from the bark of birch trees. While betulin is abundantly available in the bark, betulinic acid is present in scarce quantities in nature. However, betulinic acid can be conveniently synthesized from betulin via simple redox manipulations. Betulinic acid shows selective cytotoxicity profile against cancer cells in vitro while being relatively safe for normal cells. One of the challenges for the clinical development of betulinic acid is its lack of aqueous solubility. The three key structural features of betulin/betulinic acid that have been routinely exploited for structural modifications to enhance their …

Heme Dissociation From Myoglobin In The Presence Of The Zwitterionic Detergent N,N-Dimethyl-N-Dodecylglycine Betaine: Effects Of Ionic Liquids, Eric M. Kohn, Joshua Y. Lee, Anthony Calabro, Timothy Vaden, Gregory A. Caputo

College of Science & Mathematics Departmental Research

We have investigated myoglobin protein denaturation using the zwitterionic detergent Empigen BB (EBB, N,N-Dimethyl-N-dodecylglycine betaine). A combination of absorbance, fluorescence, and circular dichroism spectroscopic measurements elucidated the protein denaturation and heme dissociation from myoglobin. The results indicated that Empigen BB was not able to fully denature the myoglobin structure, but apparently can induce the dissociation of the heme group from the protein. This provides a way to estimate the heme binding free energy, ΔGdissociation. As ionic liquids (ILs) have been shown to perturb the myoglobin protein, we have investigated the effects of the ILs 1-butyl-3-methylimidazolium chloride (BMICl), 1-ethyl-3-methylimidazolium acetate (EMIAc), …

Exploring The Structural Transformation Mechanism Of Chinese And Thailand Silk Fibroin Fibers And Formic-Acid Fabricated Silk Films, Qichun Liu, Fang Wang, Zhenggui Gu, Qingyu Ma, Xiao Hu

College of Science & Mathematics Departmental Research

Silk fibroin (SF) is a protein polymer derived from insects, which has unique mechanical properties and tunable biodegradation rate due to its variable structures. Here, the variability of structural, thermal, and mechanical properties of two domesticated silk films (Chinese and Thailand B. Mori) regenerated from formic acid solution, as well as their original fibers, were compared and investigated using dynamic mechanical analysis (DMA) and Fourier transform infrared spectrometry (FTIR). Four relaxation events appeared clearly during the temperature region of 25 °C to 280 °C in DMA curves, and their disorder degree (fdis) and glass transition temperature (Tg) were predicted using …

Efforts Towards The Discovery Of Novel Methods For The Synthesis Of Pharmacologically Relevant Molecular Scaffolds, Graham Joseph Haun

Theses and Dissertations

With the introductions of pharmaceuticals into modern day society many people have been using them to improve their lives. Due to this high increase in demand along with the ever-growing concern of environmental impact pharmaceutical companies have been pressed to synthesis new and existing drugs at a higher rate. This increased rate can cause low yield drugs or have a heavy environmental impact. As the use of pharmaceuticals becomes more widespread the need for greener and simpler organic synthesis methods to make these pharmaceuticals becomes more needed.

Herein is reported the methodological development of different pharmacologically relevant scaffolds. This work …

Comparative Investigation Of Thermal And Structural Behavior In Renewably Sourced Composite Films Of Even-Even Nylons (610 And 1010) With Silk Fibroin, Kayla Calloway, Ye Xue, Vincent Altimari, Guoxiang Jiang, Xiao Hu

College of Science & Mathematics Departmental Research

As the average life expectancy continues to increase, so does the need for resorbable materials designed to treat, augment, or replace components and functions of the body. Naturally occurring biopolymers such as silks are already attractive candidates due to natural abundance and high biocompatibility accompanied by physical properties which are easily modulated through blending with another polymer. In this paper, the authors report on the fabrication of biocomposite materials made from binary blends of Bombyx mori silk fibroin (SF) protein and renewably sourced low molecular weight nylon 610 and high molecular weight nylon 1010. Films were characterized using scanning electron …

The Geotraces Intermediate Data Product 2017, R. Schlitzer, Lauren Kipp

School of Earth & Environment Departmental Research

The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and …

Computer Organization With Mips, Seth D. Bergmann

Open Educational Resources

This book is intended to be used for a first course in computer organization, or computer architecture. It assumes that all digital components can be constructed from fundamental logic gates. The book begins with number representation schemes and assembly language for the MIPS architecture, including assembler directives, pseudo-operations, and floating point instructions. It then describes the machine language instruction formats, and shows the student how to translate an assembly language program to machine language. This is followed by a chapter which describes how to construct an assembler for MIPS. This chapter may be omitted without loss of continuity. This is …

Information Foraging Through The Analysis Of Semantic Network Topology, Phillip J. Dibona

Theses and Dissertations

Information seekers are posed with multiple challenges in gathering an unbiased and comprehensive body of information. The costs of analyzing documents often drive searches toward a small subset of documents. Additionally, modern search tools may reinforce the confirmation bias of users by providing only those documents that closely match their search query. The end result is a decision or hypothesis that is ill-considered and substantiated by potentially biased information. Information seekers need an information foraging tool that can help them explore the document corpus to find relevant topics and text snippets, while finding the hidden information that may be buried …

Moving Target Defense For Securing Scada Communications, Vahid Heydari

College of Science & Mathematics Departmental Research

In this paper, we introduce a framework for building a secure and private peer to peer communication used in supervisory control and data acquisition networks with a novel Mobile IPv6-based moving target defense strategy. Our approach aids in combating remote cyber-attacks against peer hosts by thwarting any potential attacks at their reconnaissance stage. The IP address of each host is randomly changed at a certain interval creating a moving target to make it difficult for an attacker to find the host. At the same time, the peer host is updated through the use of the binding update procedure (standard Mobile …

Primordial Black Hole Atoms, David Zwick, Tyler Hanover, Brian Nepper

STEM Student Research Symposium Posters

Primordial black holes are thought to have been formed at the early stages of the universe in the presence of non-homogeneous density distributions of dark matter. We are working under the assumption that dark matter consists of elementary low mass particles, specifically, spin 1/2 fermions. We further assume that dark matter is electrically neutral, thus its main interaction is gravitational. We investigate dark matter spin 1/2 fermions in orbit around a black hole atom and consider mass ranges for which the quantum description is appropriate. Solutions to the Dirac equation are utilized to describe the radial mass distribution of primordial …

Using Data Visualization To Inform Machine Learning Approaches, Eric N. Zielonka, Aleksandr Fritz

STEM Student Research Symposium Posters

Machine learning with big data is a complicated task to tackle. Using data visualizations, one can find trends, anomalies, and patterns to help select the appropriate approach to the problem in machine learning. Using 2D visualizations, we’ve displayed flight data on interactive maps, visualizing density and property changes in an area. We’ve also used frequency histograms to view the quantitative properties of each point to look for trends. Using scatterplots, anomalies in data collection were found. Other plots confirmed previously found trends and initial thoughts about the data. These visualizations helped inform a machine learning approach to our problem and …

Lingering Radioactivity At The Bikini And Enewetak Atolls, Ken O. Buesseler, Matthew A. Charette, Steven M. Pike, Paul B. Henderson, Lauren Kipp

School of Earth & Environment Departmental Research

We made an assessment of the levels of radionuclides in the ocean waters, seafloor and groundwater at Bikini and Enewetak Atolls where the US conducted nuclear weapons tests in the 1940's and 50's. This included the first estimates of submarine groundwater discharge (SGD) derived from radium isotopes that can be used here to calculate radionuclide fluxes in to the lagoon waters. While there is significant variability between sites and sample types, levels of plutonium (239,240Pu) remain several orders of magnitude higher in lagoon seawater and sediments than what is found in rest of the world's oceans. In contrast, levels of …

Molecular Dynamics Study Of Homo-Oligomeric Ion Channels: Structures Of The Surrounding Lipids And Dynamics Of Water Movement, Thuy Hien Nguyen, Catherine C. Moore, Preston B. Moore, Zhiwei Liu

College of Science & Mathematics Departmental Research

Molecular dynamics simulations were used to study the structural perturbations of lipids surrounding transmembrane ion channel forming helices/helical bundles and the movement of water within the pores of the ion-channels/bundles. Specifically, helical monomers to hexameric helical bundles embedded in palmitoyl-oleoyl-phosphatidyl-choline (POPC) lipid bilayer were studied. Two amphipathic α-helices with the sequence Ac-(LSLLLSL)3-NH2 (LS2), and Ac-(LSSLLSL)3-NH2 (LS3), which are known to form ion channels, were used. To investigate the surrounding lipid environment, we examined the hydrophobic mismatch, acyl chain order parameter profiles, lipid head-to-tail vector projection on the membrane surface, and the lipid headgroup vector projection. We find that the lipid …

Preparation Of Polymeric Materials From Bio-Renewable Sources, Jason Douglas Smith

Theses and Dissertations

The focus of this project was to develop methodologies for the preparation of novel polymeric materials from bio-renewable sources. In order to complete this task we needed (a) unfettered access to bio-based materials and ways to convert them to value needed chemicals, as well as, (b) reaction protocols that would allow greater diversity during the synthesis of polymeric compounds so as to affect the properties of these materials.

Our research group has a background in converting plant-based materials like cellulose into value added chemicals employing catalytic reactions. The polymerization of these monomers was then conducted utilizing the Baylis-Hillman reaction. The …

Semi-Synthesis Of A Novel Library Of Alkaloids As Potential Selective Analgesics, Brittany M. Gallagher

Theses and Dissertations

Semi-synthetic compounds are an important part of the therapeutic drug discovery process. The goals of the project were to synthesize different generations of matrine analogues in order to gain many opportunities to manipulate the core structure. The long-term goal was, by manipulating the structure, the possibility to increase the biological activity of the original compound while also decreasing the toxicity. The first-generation matrine analogue allows for a synthesis similar to the Striker reaction producing aminonitriles. An alkyne coupling reaction was also possible with the modification, producing propargyl-amines. Both of the reactions resulted in the addition of a triple bond substituent …

Increased Fluxes Of Shelf-Derived Materials To The Central Arctic Ocean, Lauren Kipp, Matthew A. Charette, Willard S. Moore, Paul B. Henderson, Ignatius G. Rigor

School of Earth & Environment Departmental Research

Rising temperatures in the Arctic Ocean region are responsible for changes such as reduced ice cover, permafrost thawing, and increased river discharge, which, together, alter nutrient and carbon cycles over the vast Arctic continental shelf. We show that the concentration of radium-228, sourced to seawater through sediment-water exchange processes, has increased substantially in surface waters of the central Arctic Ocean over the past decade. A mass balance model for 228Ra suggests that this increase is due to an intensification of shelf-derived material inputs to the central basin, a source that would also carry elevated concentrations of dissolved organic carbon and …